public class Set : IEnumerable
    {
        public class SetEnumerator : IEnumerator
        {
            int index;
            Set set = null;

            public bool MoveNext()
            {
                index++;
                if (index >= set.GetSize())
                    return false;
                else
                    return true;
            }

            public object Current {
                get { return set.GetAtIndex(index); }
            }

            public void Reset()
            {
                index = -1;
            }

            public SetEnumerator(Set mySet)
            {
                this.set = mySet;
                Reset();
            }
        }

        public IEnumerator GetEnumerator()
        {
            return new SetEnumerator(this);
        }